Stapler nail Sealing version case sealer MPC-50N is mainly used to seal the top flap with a nail after the flap fold closing, usually also with a tape seal nail at the back to protect nails from rusting; they are mainly used in industries with a high added value or long storage time. At the same time, it is used in the process of automated packaging lines, but also with the box forming bottom stapler sealing erecting machine common application.